1,072 research outputs found
Developing critical reading, thinking and discussion skills among students at a Masters level using virtual learning environment
Students entering higher education at Masters level often struggle to develop skills of critical reading, discussion and analysis. That lack of skills often affects the quality of students’ written coursework, even if such work shows an extensive knowledge and understanding of the topic. Academic literature suggests that skills, including cognitive ones, are best developed by repetition. However, even though graduate programs usually offer students lectures and tutorials on critical thinking and analysis, they often lack teaching capacity to repeat those activities until a desired level of students’ skills is achieved. This paper aims to introduce a teaching activity that would allow a repetition essential for developing the desired skills, which would at the same time require minimum teaching resources to support the activity. The proposed skill repetition activity took a form of generic Quizzes with automotive feedback embedded in Virtual Learning Environment. The students were asked to evaluate several academic articles by answering generic Quiz questions on the following 6 themes: purpose, literature review, objectives, research methods, findings and conclusions of an article. The students received an instantaneous feedback after submitting their answers by being able to see the answers given by their tutors on the same paper. The results were later discussed in class. The effectiveness of the developed on-line Quizzes were tested at two modules: one core and one elective, which have the same assessment type; summative assignment consisting of 2500 words report. The MSc course in question is delivered by face-to-face teaching at two locations: at one location it is delivered via traditional classroom based teaching, on other — via blended learning. Both cohorts were included. The success of the proposed approach was judged based on the following criteria:
- students' performance in their first written submission at the end of the semester compared with performance on the same submission showed in the previous year;
- improvement of individual students’ skills, based on the improvement of their answers in each successive quiz as compared to tutors' answers;
- a feedback about those quizzes received from the students;
- amount of teaching resources required to support the quizzes.
So far we have only marks for student's submission for one module, however, the paper will report findings for both modules. The findings revealed that:
- in comparison to the previous year, students’ average mark in their first written submission has increased from 'good' to ‘very good’; the spread of marks within the cohort was narrower; the spread of marks between a first and a second supervisor was substantially reduced.
- the results from successive quizzes showed a gradual improvement in individual student’s critical thinking and analysis skills.
- feedback from the students revealed that they found the quizzes activities helpful in developing their skills of critical reading of published literature.
- the amount of teaching resources needed for a continuous support of the quizzes was reduced to a minimum.
The study revealed a value of a proposed activity in developing students' skills of critical reading, discussion and analysis. Some limitations were also revealed, such as a need for substantial initial teaching resources. It would also be beneficial to replicate a study on a bigger cohort
The law of action and reaction for the effective force in a nonequilibrium colloidal system
We study a nonequilibrium Langevin many-body system containing two 'test'
particles and many 'background' particles. The test particles are spatially
confined by a harmonic potential, and the background particles are driven by an
external driving force. Employing numerical simulations of the model, we
formulate an effective description of the two test particles in a
nonequilibrium steady state. In particular, we investigate several different
definitions of the effective force acting between the test particles. We find
that the law of action and reaction does not hold for the total mechanical
force exerted by the background particles, but that it does hold for the
thermodynamic force defined operationally on the basis of an idea used to
extend the first law of thermodynamics to nonequilibrium steady states.Comment: 13 page
A dynamical theory of homogeneous nucleation for colloids and macromolecules
Homogeneous nucleation is formulated within the context of fluctuating
hydrodynamics. It is shown that for a colloidal or macromolecular system in the
strong damping limit the most likely path for nucleation can be determined by
gradient descent in density space governed by a nontrivial metric fixed by the
dynamics. The theory provides a justification and extension of more heuristic
equilibrium approaches based solely on the free energy. It is illustrated by
application to liquid-vapor nucleation where it is shown that, in contrast to
most free energy-based studies, the smallest clusters correspond to long
wavelength, small amplitude perturbations.Comment: final version; 4 pages, 2 figure
Dietary fish oil preserves cardiac function in the hypertrophied rat heart
Regular fish or fish oil intake is associated with a low incidence of heart failure clinically, and fish oil-induced reduction in cardiac remodelling seen in hypertrophy models may contribute. We investigated whether improved cardiac energy efficiency in non-hypertrophied hearts translates into attenuation of cardiac dysfunction in hypertrophied hearts. Male Wistar rats (n 33) at 8 weeks of age were sham-operated or subjected to abdominal aortic stenosis to produce pressure-overload cardiac hypertrophy. Starting 3 weeks post-operatively to follow initiation of hypertrophy, rats were fed a diet containing 10% olive oil (control) or 5% fish oil (ROPUFA® 30 (17% EPA, 10% DHA))+5% olive oil (FO diet). At 15 weeks post-operatively, ventricular haemodynamics and oxygen consumption were evaluated in the blood-perfused, isolated working heart. Resting and maximally stimulated cardiac output and external work were >60% depressed in hypertrophied control hearts but this was prevented by FO feeding, without attenuating hypertrophy. Cardiac energy efficiency was lower in hypertrophy, but greater in FO hearts for any given cardiac mass. Coronary blood flow, restricted in hypertrophied control hearts, increased with increasing work in hypertrophied FO hearts, revealing a significant coronary vasodilator reserve. Pronounced cardiac dysfunction in hypertrophied hearts across low and high workloads, indicative of heart failure, was attenuated by FO feeding in association with membrane incorporation of n-3 PUFA, principally DHA. Dietary fish oil may offer a new approach to balancing the high oxygen demand and haemodynamic requirements of the failing hypertrophied heart independently of attenuating hypertroph
Extended Clausius Relation and Entropy for Nonequilibrium Steady States in Heat Conducting Quantum Systems
Recently, in their attempt to construct steady state thermodynamics (SST),
Komatsu, Nakagwa, Sasa, and Tasaki found an extension of the Clausius relation
to nonequilibrium steady states in classical stochastic processes. Here we
derive a quantum mechanical version of the extended Clausius relation. We
consider a small system of interest attached to large systems which play the
role of heat baths. By only using the genuine quantum dynamics, we realize a
heat conducting nonequilibrium steady state in the small system. We study the
response of the steady state when the parameters of the system are changed
abruptly, and show that the extended Clausius relation, in which "heat" is
replaced by the "excess heat", is valid when the temperature difference is
small. Moreover we show that the entropy that appears in the relation is
similar to von Neumann entropy but has an extra symmetrization with respect to
time-reversal. We believe that the present work opens a new possibility in the
study of nonequilibrium phenomena in quantum systems, and also confirms the
robustness of the approach by Komtatsu et al.Comment: 19 pages, 2 figure
A note on the violation of the Einstein relation in a driven moderately dense granular gas
The Einstein relation for a driven moderately dense granular gas in
-dimensions is analyzed in the context of the Enskog kinetic equation. The
Enskog equation neglects velocity correlations but retains spatial correlations
arising from volume exclusion effects. As expected, there is a breakdown of the
Einstein relation relating diffusion and
mobility , being the temperature of the impurity. The kinetic theory
results also show that the violation of the Einstein relation is only due to
the strong non-Maxwellian behavior of the reference state of the impurity
particles. The deviation of from unity becomes more significant as
the solid volume fraction and the inelasticity increase, especially when the
system is driven by the action of a Gaussian thermostat. This conclusion
qualitatively agrees with some recent simulations of dense gases [Puglisi {\em
et al.}, 2007 {\em J. Stat. Mech.} P08016], although the deviations observed in
computer simulations are more important than those obtained here from the
Enskog kinetic theory. Possible reasons for the quantitative discrepancies
between theory and simulations are discussed.Comment: 6 figure
Representation of nonequilibrium steady states in large mechanical systems
Recently a novel concise representation of the probability distribution of
heat conducting nonequilibrium steady states was derived. The representation is
valid to the second order in the ``degree of nonequilibrium'', and has a very
suggestive form where the effective Hamiltonian is determined by the excess
entropy production. Here we extend the representation to a wide class of
nonequilibrium steady states realized in classical mechanical systems where
baths (reservoirs) are also defined in terms of deterministic mechanics. The
present extension covers such nonequilibrium steady states with a heat
conduction, with particle flow (maintained either by external field or by
particle reservoirs), and under an oscillating external field. We also simplify
the derivation and discuss the corresponding representation to the full order.Comment: 27 pages, 3 figure
Renormalization group study of the conductances of interacting quantum wire systems with different geometries
We examine the effect of interactions between the electrons on the
conductances of some systems of quantum wires with different geometries. The
systems include a wire with a stub in the middle, a wire containing a ring
which can enclose a magnetic flux, and a system of four wires which are
connected in the middle through a fifth wire. Each of the wires is taken to be
a weakly interacting Tomonaga-Luttinger liquid, and scattering matrices are
introduced at all the junctions. Using a renormalization group method developed
recently for studying the flow of scattering matrices for interacting systems
in one dimension, we compute the conductances of these systems as functions of
the temperature and the wire lengths. We present results for all three regimes
of interest, namely, high, intermediate and low temperature. These correspond
respectively to the thermal coherence length being smaller than, comparable to
and larger than the smallest wire length in the different systems, i.e., the
length of the stub or each arm of the ring or the fifth wire. The
renormalization group procedure and the formulae used to compute the
conductances are different in the three regimes. We present a
phenomenologically motivated formalism for studying the conductances in the
intermediate regime where there is only partial coherence. At low temperatures,
we study the line shapes of the conductances versus the electron energy near
some of the resonances; the widths of the resonances go to zero with decreasing
temperature. Our results show that the conductances of various systems of
experimental interest depend on the temperature and lengths in a non-trivial
way when interactions are taken into account.Comment: Revtex, 17 pages including 15 figure
Transport coefficients for dense hard-disk systems
A study of the transport coefficients of a system of elastic hard disks,
based on the use of Helfand-Einstein expressions is reported. The
self-diffusion, the viscosity, and the heat conductivity are examined with
averaging techniques especially appropriate for the use in event-driven
molecular dynamics algorithms with periodic boundary conditions. The density
and size dependence of the results is analyzed, and comparison with the
predictions from Enskog's theory is carried out. In particular, the behavior of
the transport coefficients in the vicinity of the fluid-solid transition is
investigated and a striking power law divergence of the viscosity in this
region is obtained, while all other examined transport coefficients show a drop
in that density range.Comment: submitted to PR
Mott localization in the correlated superconductor Cs3C60 resulting from the molecular Jahn-Teller effect
Cs3C60 is a correlated superconductor under pressure, but an insulator under ambient conditions. The mechanism causing this insulating behavior is the combination of Mott localization and the dynamic Jahn-Teller effect. We show evidence from infrared spectroscopy for the dynamic Jahn-Teller distortion. The continuous change with temperature of the splitting of infrared lines is typical Jahn-Teller behavior, reflecting the change in population of solid-state conformers. We conclude that the electronic and magnetic solid-state properties of the insulating state are controlled by molecular phenomena. We estimate the time scale of the dynamic Jahn-Teller effect to be above 10^(-11) s and the energy difference between the conformers less than 20 cm-1
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